Lucien



Jan. 31, 1956 R. LuclEN SELF-REGULATING FEED-PUMP Filed Nov. 14, 1952 INVENTOR RENE LucslENV 37 AGENTS SELF-REGULATIN G FEED-PUMP Ren Lucien, Paris, France, assignor to Societe dlInventions Aeronautiques et Mecaniques S. I. A. M., Fribourg, Switzerland, a corporafion of Switzerland My invention is concerned with a constant stroke piston feed pump the yield of which is automatically nited States PatentO controlled as a function of the back pressure and particularly in inverse ratio to the back pressure and may even sink to zero as the latter reaches a predetermined value.

It is characterized thereby that, upon the back pressure reaching a definite upper limit, a sleeve in which the pump barrel is slidably mounted is displaced along the same by the action of said back pressure and thereby progressively uncovers a series of ports drilled in a row through the cylinder wall, which thereby are set into communication through a channel drilled through the pump plunger with the suction side of the cylinder.

My invention will be explained more specifically hereinafter, reference being had to the appended sheet of drawing in which:

Figure 1 is a'longitudinal sectional view of a one cylinder pump designed according to my invention.

Figure 2 is a similar view of a multi cylinder pump in which the cylinders are arranged the same as in a revolver barrel.

' 2 pressure it is acted upon by the discharged liquid from the pump.

Upon the delivery pressure exceeding a definite value, the spring 22 yields, the sleeve 9 is moved downwards and uncovers one of the ports 10 through which a part of the liquid sucked in is allowed to fiow out freely and without pressure, for said liquid communicates at least in 'a part of the piston stroke, with the port 10, through Channels 11 and 12 and chamber 14.

Consequent to a further increase in the back pressure, spring 22 yields on and a second port 10 is uncovered, whereby the outflow of liquid is ncreased correspondingly. According to the member and the dimension of the ports 10 that are uncovered, it may be contemplated to provide such a number of ports 10 and so to dimension the same as to ensure that the whole of the liquid escape through said ports once the back pressure has reached a definite evalue, i. e. once the spring has yielded to a definite degree.

Obviously, any mechanism performing the movement of the sleeve responsive to the back pressure may be used instead of the piston shown and described which is only given by way of example. The piston may be replaced by a diaphragm and the transmission mechanism may comprise several alternatives.

My invention Will now be described, by way of no limitative exemplification, in its application to a plurality of pistons reciprocable in as many cylinders bored from a solid barrel the same as they are in the barrel of a revolver pistol.

The pump comprises a casing 30 composed of the v assembled parts 30a, 30h, 30a fitted with a suction mouth- Similar references designate similar parts in either figure.

As shown in Figure 1, my pump includes a cylinder 1 in which a plunger 2 is slidably received to which a reciprocatory movement of constant stroke is imparted.

The fluid is sucked into the cylinder through a tail pipe a 3 and forced out past a check valve 6, housed in a valve box 5 and urged to closed position by a spring 7, through a further tail pipe 4. v

According to my invention, an externally cylindrical portion 3 of the cylinder 1, is surrounded by a sleeve 9. Said portion 8 of cylinder 1 is provided with a series of longitudinally stepped ports 10, while the plunger 2 is axially drilled from its Working end with a channel 11 connected to a perpendicular channel 12 which is drilled in a portion 13 of the plunger 2 the outer diameter of which has been reduced in order to provide for an annular chamber 14 arranged between the plunger and the cylinder.

On the delivery side of the liquid under pressure there is connected a duct for setting in communication the discharged liquid with one of the sides of a piston 15 urged in a direction reverse to the pressure it is acted upon by the liquid, by an antagonistic force, for instance, that of a suitably calibrated spring.

Upon the back pressure overcoming the resistance of the spring, the latter will yield to the action and thereby allow the piston of transmitting its action through any suitable means to the sleeve 9. In the figure, there has been shown, by way of exemplification, a mechanism composed of a piston 15 slidably received in a cylinder and provided with a rod 17 on which abuts the one end of a lever 18 pivoted at 19 and the other end 20 of which is received in an annular groove milled in the skirt of a flange 21 of sleeve 9; an antagonistic spring 22 urges the piston 15 into a direction reverse to the piece 3, a delivery mount-piece 4 and a mouth-piece 31 adapted to let out such liquid as will be shunted from the fiow of liquid upon the back pressure exceeding a definite value.

Mounted on ball bearings 32, 33 within the pump barrel 30 is a hollow shaft 34 formed at its bottom end with a likewise skew flange 35 to which is secured a Wearing ring 36. Said hollow shaft 34 is driven as shown through a gear wheel 37 or in any other desired manner by a prime mover (not shown).

Inside the casing 30 and equally spaced around the axis of the barrel 30 and coaxially therewith are a number of pumps with Vertical axis of the kind, already referred to one of which is shown in 1 in cross section in the right half of Figure 2. Each pump communicates through apertures 3a with an annular chamber 3b which in turn communicates with the suction mouthpiece 3. Each plunger 2 is formed at its top end with a head 38,`of bi-frustoconical Shape. The discharge chambers of the individual pumps are connected with the discharge duct by means of ducts 4a.

Arranged coaxially with the casing 30 is a cylindrical pillar 39 as an extension of the bottom 30a of the casing. At the end of said pillar is threaded a kneecap 41 capped with an externally cylindrical socket 42 which is slidably received in a cap 43 which is urged upwardly by springs 44. Said cap 43 is forrned at its bottom end With a rim 45 provided on its periphery with apertures in which the upper ends of the plungers 2 are made a loose fit. The plunger heads 38 are squeezed between said wearing ring 36 and said ring 45 and are lowered and lifted at each rotation of the hollow shaft 34 and the individual pumps operate as' above described.

It will be appreciated that the actuation of said pistons becomes entirely positive.

This leads to following advantages:

(a) The springs for the individual return of the plungers as are necessary in known arrangements involving one single swash plate are done away with;

(b) The plunger heads engage the wearing surfaces on generatri'c'e's' o'fcone's;

(c) The masses to be movefd are reduced.

Moreoventhe provision of: the spring 44-; urg'ing the rim 457 upwards constitutes an automatic wear take uptdevice.

The automatic] regulation. accordingv to the invention takes place as follows:

The pillar 39 isl bored longitudinally by channels 46 which connect the delivery tail pipe 4 with a chamber 47., arranged between the pillar 39 and the knee-cap 41. In the pillar 39 `is housedalong its axis, a cylinder in which is slidably received a piston 48. The pillar 39 is slidably received inZ a cylinderv 49provided with a fiange 50 the edges-` of which are received in the: pcripherall grooves of the sleeves 9; A return spring. 51 urges the flange 50 upwardly. The cylinder 49 is integral with a rod 52l that passes` through the pillar 39 andV is slidably received in. a` Vertical slot 53 drilled through the latter. The back pressure prevailing in the chamber 47 onl the piston 48 aims to urge it downwards and, accordingly, to lower the cylinder 49 and the fiange 50, actingl against theV spring 51.. Upon the saidl pressure exceeding a certain limit, the cylinder 49 is moved downwards thereby comprising the spring 51 and moving downwards the sleeves 9 that progressively uncover the ports 10. lt may be managed to obtain that beyond a certain lowering of the cylinder 49 and consequently a definite back pressure, the whole amount of liquid sucked by the pumps is let olf through said ports. The liquid is collected in the pump unit barrel and discharged through the tail pipe 31, whence it may be returned to the suction tank unless it is used for any t desired purpose.

Amongstthe advantages aforded by the pump according to my invention, vthere may be mentioned the following ones:

(a) The load on the mechanism is directly related to the work output;

(b) There is no engagement between the regulating `means and the working mechanism and therefore no parasitic effort.

It will be appreciat'ed that my invention is likewise applicable to other multi-cylinder pumping units in which the pumps are arranged either in one row or in a V or radially.

Iclaim:

1. A wherein the output of the pump is automatically controlled in inverse ratio to the back-pressure of the pump When said back-pressure exceeds a predetermined value, said pump comprising at least one cylinder, a piston slidable in the cylinder and closing oneV end thereof, a supply port opening into the cylinder, a check valve self-regulating constant-stroke piston pumpl closing the other end of the cylinder, at least one passageway' extendng through the piston and' having one end communicating with the supply port during a portion of the working stroke of the piston in the cylinder, the cylinder and piston cooperating to define an annular Chamber surrounding the piston in the cylinder and communicating With-the passageway during the whole Working stroke of the piston, a series of relief ports opening out of the,v cylinder and spaced axially thereof along the zone occupiedz by the annular chamber duringv the Working stroke of the piston, a sleeve slidable on the cylinder along said zone, and means responsive to backpressure of the pump and including a duet connected to receive: fluid3 delivered thereto by said check valve, a member exposed to said fluid and movable upon delivery of fluid to said duct, and a mechanical connection between said member and sleeve for sliding the sleeve along said zone when the back-pressure exceeds a'predeterminedvalue.v

2. A'pump as` in claim 1 wherein said pressure-responsive means comprisef an' auxiliary regulating piston havingx a working face exposed to the back-pressure of the pump, and oppositely acting resilient means calibrated to said'gpredetermined value. V

3. Az pump as in claim- 2 further comprising an auxiliary cylinder for the regulating piston, a sliding ring sur-rounding thel auxiliary cylinder and operatively connec-ted: to the regulating piston for reciprocation thereby, and mechanical means connecting the ring with the sleeve.

4. A barrel-type'- pump comprising a plurality of individual self-regulating pumps as in claim 3 and a single Outlet duet connectedf in common to the pressure side of each individual pump.

5,. A barrel-type pump comprising a plurality of individual' self-regulating pumps as in claim 2 and a single outlet .duct connected in common to the pressure side of each individual pump.

6. A barrel-type pump comprising a plurality of individual self-regulating'pumps as in claim 1 and a single outlet ductV connected in common to the pressure side of each-individual pump.

References Cited in the file of this patent UNITED STATES PATENTS 

